There is one thing which I feel obliged, though with extreme hesitation and reluctance, to say to my readers in this place, because the time has come when something ought to be said, and there seems to be no other place available for saying it. For many years letters--often in a high degree interesting and pleasant to receive--have been coming to me from persons with whom I am not acquainted, and I have always done my best to answer them. It is a long time since such letters came to form the larger part of a voluminous mass of correspondence. The physical fact has assumed dimensions with which it is no longer possible to cope. If I were to answer all the letters which arrive by every mail, I should never be able to do another day's work. It is becoming impossible even to _read_ them all; and there is scarcely time for giving due attention to one in ten. Kind friends and readers will thus understand that if their queries seem to be neglected, it is by no means from any want of good will, but simply from the lamentable fact that the day contains only four-and-twenty hours. CAMBRIDGE, _October 25, 1891._ CONTENTS. CHAPTER I. ANCIENT AMERICA. PAGE The American aborigines 1 Question as to their origin 2, 3 Antiquity of man in America 4 Shell-mounds, or middens 4, 5 The Glacial Period 6, 7 Discoveries in the Trenton gravel 8 Discoveries in Ohio, Indiana, and Minnesota 9 Mr. Cresson's discovery at Claymont, Delaware 10 The Calaveras skull 11 Pleistocene men and mammals 12, 13 Elevation and subsidence 13, 14 Waves of migration 15 The Cave men of Europe in the Glacial Period 16 The Eskimos are probably a remnant of the Cave men 17-19 There was probably no connection or intercourse by water between ancient America and the Old World 20 There is one great American red race 21 Different senses in which the word "race" is used 21-23 No necessary connection between differences in culture and differences in race 23 Mr. Lewis Morgan's classification of grades of culture 24-32 Distinction between Savagery and Barbarism 25 Origin of pottery 25 Lower, middle, and upper status of savagery 26